Pneumatic sounder



Patented July 26, 1949 PNEUMATIC SOUNDER Walter siegerflwestchester,Ill., assignor to Howard Foundry Company, Chicago, 11]., a corporationof Illinois Application July 20, 1945, Serial No. 606,244

3 Claims. (01. 116- 142) This invention relates to a pneumatic sounderwhich is designed to produce a loud, clear signal such as is required inindustrial plants, harbor installations, fast-moving trains, etc. In theaccomplishment of my purposes, I utilize a wind chest having a dischargeopening which is diaphragm-controlled, together with a screen forseparating solid particles from the air in its movement through the windchest, In such a construction, the screen may vibrate sympatheticallywith the diaphragm whereby the separated solid particles are dislodgedto fall into a trap to be discharged through a blow-out port whenever aclosure therefor is removed. In conjunction with the wind chest I alsoprovide a resonator into Whose chamber is discharged the blasts orpulsations of air when and as released by the operation of thediaphragm.

A device of this kind is subjected to very rigorous service, and sinceit may be exposed also to any and all weather conditions, I prefer toemploy bronze as the principal material for its construction. However,the diaphragm itself is preferably made from heat-treated berylliumcopper to insure a life of maximum duration. A sounder embodying thefeatures of my invention will produce a maximum of sound with a minimumof air volume and pressure. The resonator may be disposed with its axishorizontally whereby to facilitate drainage therefrom of any moisturecollecting therein. The provision of a filter screen, which isself-operating to dislodge particles separated from the air, willprevent damage to the orifice seat whereon the diaphragm is rested.Morse code or other signals may also be emitted with a quick response,thereby adapting the sounder for specialized uses on trains, boats, andharbor installations.

A suggestive embodiment of my invention is set forth in the accompanyingdrawing wherein- Fig. 1 is a top plan view of the pneumatic sounder inits entirety; and

Fig. 2 is a central vertical section therethrough.

The main unit of my pneumatic sounder is a body B which is chambered toform a wind chest. For convenience and attainment of certain advantagesthe body may be provided with a separable end fitting flanged at 6 toabut a flange l on the body whereby to facilitate a union of one of theother as by means of cap screws 8. Between the flanges may be clamped inplace a screen, here shown as a perforated disc Si which extendstransversely across the wind chest.

Interiorly of the end fitting is a hollow central boss l0 through whichis an inlet orifice II. A throttle-controlled connection (not shown) tothe interior of this boss will serve to conduct air thereto for deliveryto the wind chest within the body. Surrounding this boss is an annularchannel l2 forming a trap from which a lateral passage l3 leads to ablow-out port I4 normally closed by a removable plug l5.

The opposite body end is provided with inner walls l6 which form acentral discharge opening directly opposite the, inlet orifice. Thesewalls, in conjunction with the outside walls of the body, define anannular chamber I! from which leads a lateral passage l8 extendingthrough to the exterior of the body where I have provided a collar IS.The body walls continue on beyond the annular chamber to form a shoulder20 and then a top ring 2| which is interiorly threaded for connectionwith the circular walls 22 of a cap 23 from whose top may rise a pair oflugs 24 to facilitate application of a wrench or other tool.

The inner walls It surroundin the central discharge opening form at thetop an annular seat 25 which lies in a plane that is substantiallycoincident with the circular shoulder 20 that is spaced outwardlytherefrom. A circular diaphragm 26, normally flat, is extended acrossthis end of the body, its edge portion resting on the shoulder 20 to be,there held in a fixed position by engagement therewith of the bottomedges of the walls 22 of the cap 23 when the latter is rotativelyadvanced sufflciently for this purpose. When so secured the diaphragm isadapted to contact the annular seat, thereby closing off communicationto the surrounding annular chamber.

The top ring 2| may be split at one point where a pair of outtumed ears28 are provided, each formed with a transverse opening in register withthe other to receive a bolt 29 whereby to contact and hold the ringtightly around the cap walls 22. In this way a secure friction lock isprovided. Fixedly secured within the collar I9 is the cylindrical smallend 30 of an outwardly tapering resonator R in the form of a horn. Whenso attached, perhaps with the aid of solder or other suitable connectingmedium, the chamber 3| within the resonator will be in communication,via the lateral passage l8, with the annular chamber I! which isnormally closed by the diaphragm. In operation, air which is compressedto say 50-100 lbs., is released through the inlet orifice to enter thewind chest. In passing throughthe screen, any solid particles suspendedin the air are separated therefrom to fall down into the channel trap I2from whence they may be blown out by removal of the plug l5 at anyconvenient time. The cleaned air is adapted to exert its pressure on thediaphragm, flexing it away from the annularseat sothat a blast or pufiof air is released into the resonating chamber 3|. This pulsation of airquickly exhausts itself by movement through the resonator out into theatmosphere, and in consequence produces a rare faction 1 3 V j at the,underside of the diaphragm whereby to draw it back tightly against itsseat. This com pletes one cycle or vibration of the sounder, thefrequency of which isgoverned by the natural pitch of the resonatingchamber. The air pulsations within the wind chest also producevibrations of the screen 9 which are more or less sympathetic with thoseof the diaphragm, so'that any solid particles separated out by} thescreen from the passing air will be constantly shaken off to fall intothe trap therebelow. 'The vibration of the screen is due to thescreerr'being sufiiciently flexible and to its ofiering sufiicientresistance to the passage of air through it to be flexed by thepulsations of the air jzolumn within the Wind chest.

Experience has demonstrated that the present sounder will operate to"produce with a minimum of .air volume and pressure a maximum of soundwhich is pure and free of disturbances and damping effects due tointerfering vibrations or other causes. This efficiency may beattributed in. part to the special arrangement of the discharge openingopposite the inlet orifice, the space therebe= tween providing a windchest wherein a static head will remain between pulsations whichtegether produce each sound blast When the apparatus is in operation.

I claim: V 1. A pneumatic sounder comprising, in combination, a bodydefining a wind chest for a moving a air column, the wind chest having acircular shoulder at its upper end, a horizontal diaphragm arrangedupon'the shoulder and extending transversely across the upper end of thebody, an end fitting secured to the lower end of the body and having aninlet orifice, a horizontal screen extending across the wind chest andhaving its marginal portion clariiped between the body and the endfitting and vibrated with the diaphragm by pulsationsof the air columnwithin the wind chest for disiodging any accumulation of particlesseparatedfrom saidair column, by said screen, a wall interiorly of thebodyat the upper end thereof defining with'the diaphragm an annularchamber and'fa discharge openin surrounded by the annular chamber, saidwall having a passage extending laterally from the annular chamber tothe body exterior, the upper edge of said wall forming a circular seataround the discharge opening with which the diaphragm contacts, acylindrical cap secured to the body andclamping the diaphragm upon saidshoulder and forming a closed air chamber above the diaphragm, and ahorizontal resonator in connection with the sounder body opposite thelateral passage having its axis substantially parallel with the plane ofthe diaphragm.

2. A pneumatic sounder comprising, in combination, a body defining awind chest for a moving air column, the wind chest having a circularshoulder at its upper end, a horizontal diaphragm arranged upon theshoulder and extending transversely acrossthe upper end of the body, anend fitting secured to 'the lower end of the body and provided with ahollow boss forming an inlet orifice, said end fitting'being providedadjacent the bottom with a normally closed blow-out-port, a horizontalscreen extending across the wind chest and having its marginal portionclamped between the body and the end fitting and vibrated with thediaphragm by pulsations of the air column within the wind chest fordislodgingany accumulation of particles separated from said air column,by said screen, a wall interiorly of the body at the upper ,end thereofdefining with the diaphragm an annular chamber and a discharge openingsurrounded by the annular chamber, said wall having a passage extendinglaterally from the annular chamber to the body exterior, the upper edgeof said wall forming a circular seat around; the discharge opening withwhich the diaphragm contacts, acylindrical cap secured to the body andclamping the diaphragm upon said shoulder and forming a closed airchamber above the diaphragm, and a horizontal resonator inconnectionwith the sounder body opposite the lateral passage having its axissubstantially parallel with theiplane oi the. diaphragm.

3-. A pneumatic sounder comprising, in combination, a bedy defining awind chest for a moving air column, the wind chest having a circularsioulder at its upper end and provided with an outer vertical wallrising from said shoulder and interiorly threaded and split at one sideand provided at the split portion with spaced ears, a flexiblehorizontal diaphragm arranged upon said shoulder and extendingtransversely across the upper endof the body, an end fitting secured tothe lower end of the body and provided with a hollow boss forming aninlet orifice, said end fitting being also provided with a normallyclosed blow-out port located at the bottom of the fitting, a horizontalscreen extending across the wind chest andhaving its marginal portionclamped between the body and the end fitting and vibrated with thediaphragm by pulsations of the air column within the :wind chestfordislodgin any accumulation of particles separated fromsaid air column,by said screen, a wall interiorly of the body defining with thediaphragm an annular chamber surrounding a discharge opening from whicha passageextends to the exterior of the body, theupper edges of theinwardly extending wallforniing a circular valve seat around thedischarge opening and with which the diaphragm contacts, a cylindricalcap threaded into said outer wall and clamping the diaphragm upon saidshoulder and forming a closed air chamber above the diaphragm, fasteningmeans piercin the ears of the split wall and securing the cap in itsclamping engagement with'the diaphragm and a horizontal resonator inconnection with the sounder body opposite the lateral passage having itsaxis substantially parallel with the plane of the dia phragm. w V WALTERSIEGERT.

REFERENCES CITED 7 The following reierences are of record in the file ofthis patent:

U I'I'ED STATES PATENTS Number

